The mother of all mass builders for the biceps is the STRAIGHT bar curl. Can be hard on wrists and elbows, but hits the bicep more completely than ez-curl barl. Incline dumbell curls are super mass and peak builders as well, and as in ALL biceps movements, strict form should be maintained to keep the shoulders from bearing the brunt of the load. I do cheat on my last rep, but that's all. Preacher curls are my 3rd favorite movement, and I use the ez-curl bar here to hit them from a little different angle. Use medium to close grip on the straight bar curls.
Hammer curls and reverse curls will build brachialis and add width, but do little for the bicep peak. I have found, through many years of trial and error, that my arms respond best when I work bicep and tricep the same night. Biceps respond to changing routines more than most muscle groups, and just changing your basic exercises can break you through a sticking point rather quickly.